Artificial leg



ARTIFICIAL LEG Nov. 1v1,A 1947. A. R. RCHE Filed oct'. 12, '194e 49 47 I+? I INVENTQR v i @Pegg K ROCHE Patented Nov. l1, 1947 ARTIFICIAL LEG Alfred R. Roche, Los An one-half to Charles Calif.

geles, Calif., assigner of Libman, Los Angeles,

Application October 12, 1946, Serial No. 703,065

3 Claims.

This invention relates to improvements in artiicial legs.

I A primary object of the invention is to provide an improved artificial leg wherein there is a novel construction of knee action so arranged that when weight is imposed thereon when the leg i-s in a vertical or upright position, any tendency for the leg to buckle is effectively avoided and when the foot of the leg is lifted from the ground, the lower leg portion will be started on a rearward swing relatively to the upper leg portion. As the leg is swung forwardly a novel arrangement of springs causes the lower leg portion to return to position in alignment with the upper leg portion and into a position capable of supporting the weight of the user without buckling.

Another object of the invention is to provide an artificial leg having a novel ankle and toe arrangement which is so constructed that when incorporated in a leg, particularly with the leg embodying the novel knee action herein disclosed, will enable the user t walk in a natural manner.

With the foregoing and other objects in View, which will be made manifest in the following detailed description and specifically pointed out in the appended claims, reference is had to the accompanying drawings for an illustrative embodiment of the invention, wherein:

Figure l is a longitudinal vertical section through the improved artificial leg embodying the present invention;

Fig. 2 is a, sectional view taken substantially upon the line 2-2 upon Fig. 1 in the direction indicated; and

Figs. 3 and 4 are partial views illustrating details of construction.

Referring to the accompanying drawings wherein similar reference characters designate similar parts throughout, the improved articial leg consists of an upper leg portion I0, a lower leg portion I I, a foot portion I2, and a toe portion I3. The upper and lower leg portions are preferably hollow so as to reduce weight. They are hingedly connected together by a transversely extending shaft I4. In the preferred form of construction the upper leg portion has side irons i5 and I6 rigidly'secured thereto and the lower leg portion II has corresponding side irons embedded in the walls thereof indicated at I'I and I 8. Anti-friction bearings I9 and 20 are interposed between corresponding side irons and around the shaft I4.

As will be appreciated by those skilled in the art, the axis of the shaft I4 should be slightly inclined so that the inner end of the shaft is somewhat higher than the outer end of the shaft vwhereby the lower leg will swing relatively to the upper leg in a manner corresponding to the axis of movement of a natural knee. Consequently, depending upon whether the leg is a left leg -or a right leg, the position of the shaft lll should be slightly inclined, as above stated.

At the forward sides of the side irons there are mutually engageable shoulders 2| and 22 (see Fig. 3) which will limit forward swinging movement of the upper leg portion to a vertical position or upright position with relation to the lower leg portion. In a similar manner complementary shoulders 23 and 24 are formed on the rear sides of the side irons to ultimately limit bending or turning movement of the upper leg portion relatively to the lower leg portion. The lower end of the upper leg portion extends downwardly into the top of the lower leg and a knee cap 25 preferably formed of one or more layers of heavy felt is secured at its upper edge to the upper leg portion and is suspended therefrom over the break between the upper and lower leg portions. A feature of the invention concerns the springs employed that affect the movements of the leg portions with relation to each other. Adjacent the bottom of the upper leg portion there is pivoted as at 26 a clevis 2l to which is secured a guide stem 23. This guide stem slidably extends through a ferrule 29 that is pivoted as at 30 to the underside of a bracket 3| that is mounted within the lower leg portion on the back wall thereof. A coil compressison spring 32 is compressed slightly about the guide rod 28 between the ferrule 29 and the clevis 2l. This compression spring will normally urge the lower leg portion to swing rearwardly with relation to the upper leg portion.

vAdjacent the back of the upper leg portion Ill and near the lower end thereof there is a transversely extending rod 33 that is pivoted in the upper leg portion and carries downwardly extending tapered spring seats 34. Complementary tapered spring seats 35 are pivotally mounted as at 36 upon the bracket 3|. Compression springs 3l are compressed between these spring seats and the spring seats partially enter their respective ends of these springs. These springs are so arranged that when the upper leg portion bends with relation to the lower leg portion as indicated by dotted lines on Fig. 1, the coil springs will tend to bend or buckle as indicated by dotted lines. By this arrangement after the knee of the leg has started to bend, causing the springs to buckle, the springs will offer a minimum resistance to continued bending. However, as the upper and leg portion thus causing the springs 31 to begin to buckle. started, continued bending of the knee of the leg is relatively easy. As the leg is then swung forwardly in taking a step the momentum of the lower leg tends to return it to the aligned position with the upper leg and unbuckling or straightening of the springs 31 commences. As these springs approach their straight or full line position, as illustrated in Fig. l, they become more and more effective to return the lower -leg to a `position -in alignment with the upper leg. During'this movement vof the knee of the leg the guide 'rod Y2'8'merely slides through the pivoted ferrule 2-9 enabling the spring 32 to compress and expand and serving at all rtimes to maintain this spring in proper position.

As is illustrated in Fig. 4il, the lower spring seats 35 'are provided with stops VSil engageable with stop pins 38a on the `bracket 3l so that these spring seats may never pivot rearwardly but will be maintained in a Vposition slightly inclined forwardly so that the springs 31 are constantly slightly flexed toward their buckling position.

At the bottom of the lower leg the foot portion I2 is hingedly connected to I'the lower leg portion H. To this end the foot 'portion may have a T- iron 48 mounted thereon which is vreceived in a knuckle providing memberfl attached tothe botl-torn of the lower leg portion. Rearwardly-of lthis hinge connection the foot portion is recessed as at l2 to permit of rearward swinging movement 'of vthe 'lower lleg portion lI I with relation to the foot. A'similar recess at '43 permits vof forward swinging movement of the lower `leg jH with relation 4to the foot. Opposed recesses are formed in the foot and in the lower leg portion H above and below `these clearance spaces and these recesses accommodate spring seats 44 -foroom-pressionsprings 45 and v46. These compression springs permit the lower 'leg portion to rock either forwardly or'rearwardly with relation Ato -the foot l2 but normally urge the -foot into a predetermined position with relation to the lower leg. The toe portion i3 is attached to the foot l2 Aby means of a section-of leather, composition or the-equivalent, indicated `at 41. This leather, while relatively stiff, permits -of some flexing of the toe portion relatively to -the foot. Such movement is provided by -the `clearance space indicated at 48. One or more compression springs '49 extend across the clearance space 48 land are recessed at their ends in the toe and foot respectively. These compression springs urge the 'toe i3 to remain in proper position extending 'forwardly Aof the foot portion but permit of flexing of the toe with relation Vto the foot when suohraction is required.

From the above described construction it will Ibe appreciated that the improved artificial -leg is so designed as to `enable walking in a natural -manner by -amputees The mechanism at the knee joint ofthe leg is -suchthat when the leg is lifted from the surface of the ground so Aas to be suspended, the lower compression vspring 32 is After buckling of the springs 31 has v 4 highly effective to swing the lower leg portion rearwardly. During this rearward swinging movement the compression springs 31 tend to buckle and thus resistance to the rearward swinging movement decreases as the movement progresses. When the leg is swung forwardly the compression springs 31 tend to straighten into the Vfull-line position shown in Fig. .1, andas the lower leg portion approaches the limit of its movement occasioned by the stops 2| and 22 mutually engaging, these springs exert their maximum effort to retain the lower leg in aligned position with the upper leg Il). Rocking of the leg with relation to the foot Vportion is provided by the ankle pivot and the rcornpressible springs and the arrangement at the connection of the toe is such Las to simulate natural foot action.

Various changes may be made in the details of 'construction without departing from the spirit and scope of the invention as defined by the appended claims.

claim:

`l. In anarti-iicial leg, upper `and lower leg portions pivotally connected Atogether `for -relative swinging movement therebetween, a compression 4spring connecting the upper leg portion to the lower leg portion urging the lupper lesr portion to Vassume a bent `position relative to the lower leg portion, andlcompression springs arranged behind the pivot urging the upper leg portion to assume an upright position with relation to the lower leg portion, 4the last mentioned springs befing Aarranged to :buckle when the upper leg portion swings relatively to Athe lower leg portion.

2. In anartilicial leg, upper and lower leg portions pivotally connected together for relative swinging movement therebetween, la guide stem pivotally mounted `on the lower end of the upper leg portion, va errule pivotally mounted within the lower leg portion through 'which the `guide stem vis slidable, -a compression spring disposed about the guide stem urging the upper and lower :leg portions linto bent positions with relation to eachother, compression springs arranged behind Ethe pivot. spring -seats for said compression 'springs pivotally mounted uponthe upper leg portion and lower leg portion respectively, means limiting rotary movement yof some of the spring seats, the last ymentioned compression springs being arranged to buckle when the upper 4leg portion swings relatively to the lower ieg portion and to straighten 4when the yupper leg portion assumes a position in alignment with the lower leg portion.

3. 'In an artiiicial leg, upper and lower leg portions pivotally connected together for relative swinging movement therebetween, a guide stem -pi-votally mountedon the lower end of `the upper leg portion, a ferrule -pivotally mounted within the lower lleg portion through which the guide stem Ais 'slidable, a vcompression spring disposed about the `guide stem urging the upper and lower leg portions into bent positions with relation to each other, compression springs arranged behind the pivot, spring seats for saidcompression .springs pivotally mountednpon the .upper leg .portion and lower leg `portion respectively, vmeans limiting rrotary movement .of some-of the spring seats,'the last mentioned. 'compression springs .being arranged to buckle -when ythe upper `legportion swings relatively to the lowerle'gportion and to straighten'when the upper Yleg portion assumes a position Ain alignment wit-ntheilower leg portion, :and Imeans lirniting forward swinging movement 6 of the upper leg portion with relation to the lower UNITED STATES PATENTS leg portion" Number Name Date ALFRED R ROCHE' 1,076,861 Auvll 0111.28, 1913 REFERENCES CITED 5 FOREIGN PATENTS The following references are of record in the Number Country Date le of this patent: 114,982 Great Britain Apr. 25, 1918 

